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A lack of urgency and technical expertise from governments meant New Zealand petrol contained lead for up to 20 years longer than it should have, a researcher says.
Nick Wilson, from the University of Otago's public health department in Wellington, said governments also succumbed to lobbying from the lead additives industry.
He said studies of literature and reports from 1974 to 1996 showed there was clear international evidence that lead in petrol was a serious health risk, particularly for children.
"Despite this evidence, the study shows that successive New Zealand governments and the bureaucracy consistently claimed that there was no urgency to introduce unleaded petrol in this country," Dr Wilson said.
He put part of the lack of urgency down to successful attempts by the fuel industry to stall the introduction of unleaded petrol.
"The lead additive supplier, Associated Octel, which was owned by major oil companies, provided counter information over 20 years in order to undermine international scientific studies."
Unleaded petrol became mandatory in New Zealand in 1996.
Dr Wilson said modifications in the early 1980s to the country's refinery, owned by the NZ Refining Company, also limited the ability to supply unleaded petrol.
He said the changes were made after it was already well-known that leaded petrol was a health risk.
The study said there was a "closed and negative attitude" by the bureaucracy and government to input from the wider community, including scientists and non-government organisations.
Authorities continued to claim that international research did not apply to this country, despite scientific advice to the contrary from the Royal Society of New Zealand.
"There was a credibility/denial gap a kilometre wide between scientists and governments on this issue," Dr Wilson said.
- NZPA
